The present invention relates to a work bench comprising a rotatable platform and means to clamp the rotatable platform at a fixed angular position.
It is commonplace in the machine tool art to provide a work bench having a rotary power saw fixed thereto. Wooden planks or other materials to be sawn are clamped to the work bench against a fence and cut with the power saw. In order to achieve variable angle mitre and/or bevel cutting of wooden planks it is desirable that the power saw should be capable of angular movement relative to the fence. The mitre/bevel angle can then be changed between successive cutting operations. However, the saw must be rigidly secured in a given angular position while the cutting operation is taking place.
Methods are already known for attaching a power saw to a work bench such that the saw is capable of angular movement relative to workpieces clamped to the work bench. For example, it is known to provide a mitre saw in which a rotary power saw assembly is mounted on a rotatable platform set in a fixed work surface. The blade of the power saw is thus rotatable relative to workpieces that are clamped to the fixed work surface against the fence. However, present clamping systems for maintaining the rotatable platform at a fixed angular position during the cutting operation are unsatisfactory.
For example, they are frequently directional so that the centre of the rotatable platform might not stay central in the fixed work surface. In one saw, a cam arrangement on the fixed table presses the rotatable platform across its diameter from one edge behind the fence. If the platform is loose in the table, as it must be to enable easy rotation thereof in the table, then this arrangement inevitably results in positional error of the platform in the table. At least this error is reasonably consistent and can be accommodated to some extent by the user. Another saw has the platform clamped vertically with respect to the plane of the table which means that the platform can be in any position in the table when the clamp is operated so that no accommodation of the error can be made.